Field of the Invention
The invention relates to a base plate for a rail fastening arrangement, or rail fastening point, having at least one lateral support section which has a lateral contact surface which delimits a supporting area formed on the top side of the base plate, extending over the width of the base plate and for the foot of a rail for a rail vehicle which is to be attached to the base plate. A through-hole leading from the top side to the underside of the support section is formed into an edge area of the support section abutting on the lateral contact surface, to insert a rail spike through it, this through-hole having a basic shape which is angular when viewed taken in cross-section transverse to its longitudinal axis. The surface of the edge area meets with the contact surface in an upper marginal edge which extends over the width of the base plate.
Description of Related Art
Base plates of this kind are in particular used in rail fastening points which are mounted on wooden sleepers. The base plate, on the one hand, serves to laterally guide the rail respectively fastened in the fastening point. On the other hand, the base plate distributes the load, which occurs when a rail vehicle drives over the fastening point, evenly onto the sleeper.
In order enable these functions, base plates of the kind under discussion here, which are known from practice and are used in large numbers in the field, are usually manufactured from a ferrous material which ensures that the component has a sufficiently high strength. Typically, base plates of this kind are rolled from steel as rolled-steel sections. At the same time, the known base plates usually have two support sections, each of which is arranged laterally to the supporting area of the base plate. Each of the support sections in this way forms a lateral stop collar with its contact surface assigned to the rail foot when the rail fastening point is fully mounted, via which the forces arising when the rail fastening point is driven over can be absorbed and dissipated into the sleeper.
The base plate is usually fastened to the sleeper by means of rail spikes which are driven with their spike shafts through the base plate into the sleeper. The spike head of the rail spike protrudes far enough in the direction of one side of the spike that, when it is driven into the through-hole of the base plate present near the contact surface of the respective support section, it rests, when correspondingly aligned, with its free front end on the top side of the foot of the rail to be fixed in the respective rail fastening point. It is ensured that the rail spike is positioned correctly and in a torsion-proof manner by adapting the cross-sectional shape of the respective rail spike to the angular cross-sectional shape of the assigned through-hole such that the spike fits in a form-fit manner in the through-hole when the rail fastening point is fully mounted and correspondingly any rotation around the longitudinal axis of the spike is prevented.
In order to also secure the base plate against turning on the sleeper, additional through-holes further away from the supporting area and offset in relation to one another can be formed into the support sections of the base plate, through which respectively a rail spike of the kind explained above is knocked in. In that case the rail spikes in question do not tact with their rail heads on the rail foot but rather on the top side of the respective support section and in this way fixate the base plate on the sleeper. The hole pattern in which the through-holes are arranged can be chosen such that even under high dynamic forces acting both in the horizontal direction transverse to the rail to be fastened and in the vertical direction of gravity it is ensured that the base plate is held firmly on the sleeper.
However, in practice, it has become apparent that in those areas in which the angular rail spikes are supported against the base plate cracks form which, despite the high strength and wear resistance of the steel material from which the known base plates are usually manufactured, lead to the base plates quickly becoming unfit for use.